How do you change it?
Go to Control Panel and look for Region. Change the locale to English US. enaberif's suggestion is the one I am trying as I got the "something happened" too. I have seen this suggestion elsewhere too.
If you're doing a clean install, this key should work: https://www.reddit.com/r/Windows10/..._10240_did_you_get_assigned_a_licenseproduct/
Though there's a "skip" button that should suffice too. I suspect it should activate once it boots into Windows and has proper network connectivity to verify your HWID.
That is how it should work, as long as the machine you are doing a fresh install on had Win10 activated. From what I have read it should be as simple as skipping entering any keys and just activate once online.